import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Queue;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: ZhongJinTao
 * Date: 2024-01-11
 * Time: 10:25
 */
public class MyBinomialTree {
    static class TreeNode {
        char val;
        TreeNode left;
        TreeNode right;
        public TreeNode(char val) {
            this.val = val;
        }
    }
    //创建一个二叉树
    TreeNode createTree() {
        TreeNode A = new TreeNode('A');
        TreeNode B = new TreeNode('B');
        TreeNode C = new TreeNode('C');
        TreeNode D = new TreeNode('D');
        TreeNode E = new TreeNode('E');
        TreeNode F = new TreeNode('F');
        TreeNode G = new TreeNode('G');
        TreeNode H = new TreeNode('H');
        A.left = B;
        A.right = C;
        B.left = D;
        B.right = E;
        //E.right = H;
        C.left = F;
        C.right = G;
        return A;
    }
    // 前序遍历
    void preOrder(TreeNode root) {
        if(root == null) {
            return;
        }
        System.out.print(root.val + " ");
        preOrder(root.left);
        preOrder(root.right);
    }
    // 中序遍历  -》 左根右
    void inOrder(TreeNode root){
        if(root == null) {
            return;
        }
        inOrder(root.left);
        System.out.print(root.val + " ");
        inOrder(root.right);
    }
    // 后序遍历  -》 左右根
    void postOrder(TreeNode root){
        if(root == null) {
            return;
        }
        postOrder(root.left);
        postOrder(root.right);
        System.out.print(root.val + " ");
    }
    public static int count1 = 0;
    int size1(TreeNode root) {
        if(root == null) {
            return 0;
        }
        if(root != null) {
            count1++;
        }
        size1(root.left);
        size1(root.right);
        return count1;
    }
    // 获取树中节点的个数
    int size(TreeNode root) {
        if(root == null) {
            return 0;
        }
        return size(root.left) + size(root.right) + 1;
    }
    public static int count2 = 0;
    // 获取叶子节点的个数
    int getLeafNodeCount(TreeNode root) {
        if(root == null) {
            return 0;
        }
        if(root.left == null && root.right == null) {
            count2++;
        }
        getLeafNodeCount(root.left);
        getLeafNodeCount(root.right);
        return count2;
    }
    // 子问题思路-求叶子结点个数
    int getLeafNodeCount1(TreeNode root) {
        if(root == null) {
            return 0;
        }
        if(root.left == null && root.right == null) {
            return 1;
        }
        return getLeafNodeCount1(root.left) + getLeafNodeCount1(root.right);
    }
    // 获取第K层节点的个数
    int getKLevelNodeCount(TreeNode root,int k) {
        if(root == null) {
            return 0;
        }
        if(k == 1) {
            return 1;
        }
        return getKLevelNodeCount(root.left, k - 1) + getKLevelNodeCount(root.right, k - 1);
    }
    // 获取二叉树的高度
    int getHeight(TreeNode root) {
        if(root == null) {
            return 0;
        }
        if(root.left == null && root.right == null) {
            return 1;
        }
        return Math.max(getHeight(root.left), getHeight(root.right)) + 1;
    }
    // 检测值为value的元素是否存在
    TreeNode find(TreeNode root, char val) {
        if(root == null) {
            return null;
        }
        if(root.val == val) {
            return root;
        }
        TreeNode ret1 = find(root.left, val);
        if(ret1 != null) {
            return ret1;
        }
        TreeNode ret2 = find(root.right, val);
            if(ret2 != null) {
                return ret2;
            }
        return null;
    }
    //层序遍历
    void levelOrder(TreeNode root) {
        //没有二叉树，直接返回
        if(root == null) {
            return;
        }
        //使用队列存放二叉树的元素
        Queue<TreeNode> queue = new LinkedList<>();
        queue.offer(root);
        while (!queue.isEmpty()) {
            TreeNode ret = queue.poll();
            System.out.print(ret.val + " ");
            if(ret.left != null) {
                queue.offer(ret.left);
            }
            if(ret.right != null) {
                queue.offer(ret.right);
            }
        }
    }
    // 判断一棵树是不是完全二叉树
    boolean isCompleteTree(TreeNode root) {
        if(root == null) {
            return true;
        }
        Queue<TreeNode> queue = new LinkedList<>();
        queue.offer(root);
        while (!queue.isEmpty()) {
            TreeNode ret = queue.poll();
            if(ret != null) {
                queue.offer(ret.left);
                queue.offer(ret.right);
            }else {
                break;
            }
        }
        while (!queue.isEmpty()) {
            TreeNode ret = queue.peek();
            if(ret == null) {
                queue.poll();
            } else {
                return false;
            }
        }
        return true;
    }
}
